Oat Intake and Risk of Type 2 Diabetes, Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis

Cardiovascular disease (CVD) and type 2 diabetes (T2D) remain the top disease and mortality burdens worldwide. Oats have been shown to benefit cardiovascular health and improve insulin resistance. However, the evidence linking oat consumption with CVD, T2D and all-cause mortality remains inconclusive. We conducted a comprehensive systematic review and meta-analysis of prospective cohort studies to evaluate the associations between oat consumption and risks of T2D, CVD and all-cause mortality in the general population. Five electronic databases were searched until September, 2020. Study specific relative risks (RR) were meta-analyzed using random effect models. Of 4686 relevant references, we included 9 articles, based on 8 unique studies and 471,157 participants. Comparing oat consumers versus non-consumers, RRs were 0.86 (95% CI 0.72–1.03) for T2D incidence and 0.73 (95% CI 0.5–1.07) for combined CVD incidence. Comparing participants with highest versus lowest oat intake, RRs were 0.78 (95% CI 0.74–0.82) for T2D incidence, 0.81 (95% CI 0.61–1.08) for CHD incidence and 0.79 (95% CI 0.59–1.07) for stroke. For all-cause mortality one study based on three cohorts found RR for men and women were 0.76 (95% CI 0.69–0.85) and 0.78 (95% CI 0.70–0.87), respectively. Most studies (n = 6) were of fair to good quality. This meta-analysis suggests that consumption of oat could reduce the risk for T2D and all-cause mortality, while no significant association was found for CVD. Future studies should address a lack of standardized methods in assessing overall oat intake and type of oat products, and investigate a dose-dependent response of oat products on cardiometabolic outcomes in order to introduce oat as preventive and treatment options for the public

Phytochemical characterization of turnip greens (Brassica rapa ssp. rapa): A systematic review

Objective The Turnip (Brassica rapa L. ssp. rapa) is a leaf and root vegetable grown and consumed worldwide. The consumption of Turnip has been associated with beneficial effects on human health due to their phytochemicals that may control a variety of physiological functions, including antioxidant activity, enzyme regulation, and apoptotic control and the cell cycle. The current systematic review of the literature aims to evaluate both the profile and quantity of phytochemicals commonly found in Turnip greens and to provide perspectives for further investigation. Methods This review was conducted following the PRISMA guidelines. Four bibliographic databases (PubMed, Embase, Web-of-Science and Cochrane Central Register of Controlled Trials) were searched to identify published studies until April 8th, 2020 (date last searched) without data and language restriction. Studies were included if they used samples of Turnip greens (the leaves), and evaluated its phytochemical content. Two reviewers independently evaluated the titles and abstracts according to the selection criteria. For each potentially eligible study, two reviewers assessed the full-texts and independently extracted the data using a predesigned data extraction form. Results Based on the search strategy 5,077 potentially relevant citations were identified and full texts of 37 studies were evaluated, among which 18 studies were eligible to be included in the current review. The majority of included studies were focused on identification of glucosinolates and isothiocyanates (n = 14, 82%), four studies focused on organic acids, and five studies reported phenolic component profile in Turnip greens. Among included studies nine studies (50%) provided information on phytochemi

Bioactive compounds and nutritional composition of Swiss chard (Beta vulgaris L. var. cicla and flavescens): a systematic review.

Swiss chard (Beta vulgaris L. var. cicla or flavescens) is a green leafy vegetable whose bioactive compounds have been studied due to its effects on health. We systematically reviewed the nutritional profile and bioactive composition of Swiss chard and reported their concentrations. Four main databases were searched for studies analyzing the chemical composition of Swiss chard. Screening, selection of articles, and data extraction were carried out by two independent reviewers. Twenty-eight articles of 1102 records identified by bibliographic search met our inclusion criteria for final analysis. We found a total of 192 chemical compounds categorized into 23 groups. The cicla variety was the most studied, and nutrients and phytochemicals were reported mainly on leaves. Betalains with 20% of the reported data, fats (16%), flavonoids (11%), non-flavonoid phenolics (11%), terpenes and derivatives (8%), carbohydrates (7%), and minerals (6%) were among the most reported categories. Swiss chard leaves have the highest content of fiber, sodium, magnesium, flavonoids, and vitamin C, while stems are high in potassium. Swiss chard should be considered a source of nutrients and phytochemicals, and further research is needed on identifying and quantifying other bioactive compounds and understanding their impact on health

Nutritional and phytochemical characterization of radish (Raphanus sativus): A systematic review

Background: Bioactive compounds in Raphanus sativus (radish) have been used to treat several diseases; therefore, radish has attracted increasing scientific attention due to its nutritional and phytochemical composition. Scope and approach: The available evidence on the nutrient and bioactive composition of radish was systematically assessed. Four databases (PubMed, Embase, Web of Science, and Cochrane trials) were searched, up to September 26th, 2020, for key articles assessing the chemical composition of radish. Two independent reviewers carried out screening, selection of articles, and data extraction. Key findings and conclusions: Of 1214 references, 63 met our inclusion criteria. We found 609 chemical compounds within 23 categories. Red (30% of all studied varieties), white (13%), and black (6%) radish were the most studied varieties. Nutrients and phytochemicals were reported mainly in roots and leaves. The largest categories were flavonoids (38.8% of the reported data), non-flavonoid polyphenols (8.4%), terpenes and derivatives (8.2%), fat and fatty related compounds (6.4%), and glucosinolates and breakdown products (5.6%). Leaves have high concentrations of macronutrients, calcium, potassium, sodium, fiber, fatty acids, and nonflavonoid polyphenols while sprouts are a major source of flavonoids, specifically anthocyanins, β-carotene and vitamin C. Roots are rich in non-flavonoid polyphenols together with terpenes and derivatives, and glucosinolates, the latter also highly concentrated in seeds. Raphanus sativus is a rich source of nutrients and phytochemicals. Leaves and sprouts could be considered part of a healthy diet, and together with roots, they could be explored as raw material for the development of nutraceuticals

A systematic review of phytochemicals in oat and buckwheat.

Consumption of oat and buckwheat have been associated with various health benefits that may be attributed to their nutritional composition. We performed a systematic review to evaluate the profile and quantity of bioactive compounds present in oat and buckwheat. Among 154 studies included in final analysis, 113 and 178 bioactive compounds were reported in oat and buckwheat, respectively. Total phytosterols, tocols, flavonoids and rutin content were generally higher in buckwheat, β-glucans were significantly higher in oat, while avenanthramides and saponins were characteristically present in oat. The majority of studies included in current review were published before 2010s. The heterogeneous methodological procedures used across the studies precluded our possibility to meta-analyse the evidence and raises the need for harmonization of separation and extraction methods in future studies. Our findings should further stimulate the exploration of metabolites related to identified phytochemicals and their roles in human health

Systematic Review of the Effects of Oat Intake on Gastrointestinal Health.

BACKGROUND Oats are a food source with multiple health benefits that could support beneficial bacterial groups and provide important bioactive compounds for the gut. OBJECTIVES This review explores the association between oat intake, gastrointestinal (GI) symptoms, and microbial community changes in individuals with celiac disease (CeD), irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD) and without GI disease. METHODS Four databases and Google Scholar were systematically searched from inception until April 29, 2021. Clinical trials, observational studies, and in vitro studies with human gut-derived samples were included. RESULTS There were 84 articles [23 randomized controlled trials (RCTs), 21 nonrandomized trials, 8 observational studies, and 32 in vitro studies] included. Oat intake increased total bacterial count, Lactobacilli spp., and Bifidobacterium spp. in healthy individuals and those with CeD. There was an increased concentration of short-chain fatty acids and improved gut permeability with oat intake but with no significant quality-of-life difference. In some individuals with CeD, consumption of certain oat types was associated with worsening of GI symptoms. We found no studies reporting on IBS and only 3 for IBD. The quality of RCTs showed some concerns mostly in domains of randomization (73.9%), whereas the quality of evidence of non-RCTs, observational studies, and in vitro studies was satisfactory. CONCLUSIONS Oat intake was associated with the increase of beneficial bacterial groups in individuals without GI disease and those with CeD. Most studies showed no changes in GI symptoms with oat consumption. In vitro studies in CeD provide insight to oat-sensitive individuals and their GI mucosa, but the clinical studies remain limited, precluding our ability to draw firm conclusions. The prevalence of oat sensitivity in individuals with CeD should be further explored as this could improve clinical management and facilitate inclusion of oat in the diet for this population